How Do Astronauts Brush Their Teeth in Space?

How Do Astronauts Brush Their Teeth in Space?

Virtually every aspect of human life in space is fascinating. Most of us can only imagine what it must be like to wake up, look out the window into the stars, and weightlessly get ready for work, floating around the interior of the International Space Station (ISS), orbiting over 250 miles away from Earth. Of course, at Dr. Cindy Flanagan’s dental office, we’re most interested in how astronauts maintain their spacefaring smiles. In the following blog, we’ll explain why it’s so vital that they scrub their teeth, how they do it floating in zero gravity, and what we can all learn from astronauts’ dental hygiene.

Setting the Record Straight on Oral Hygiene in Space

It’s very important for astronauts to have clean mouths, but not for the reasons most people think. According to Space.com, in a study by the European Space Agency (ESA), some people speculated that “‘in space the circumstances are different and…your bones lose calcium, and then your teeth become bad more quickly.” While it’s certainly true that astronauts “lose density while living in space,” this “isn’t the reason they need to take care of their teeth,” since this bone loss is not substantial enough to affect the jawbone and tooth sockets. Nor is the heightened importance of spacefaring dental hygiene related to “‘weightlessness,’” which might mean “‘there is no traction between the food and the teeth,’” as another person suggested.

As per the ESA, the real reason astronauts need to carefully maintain their pearly whites is due to “‘the acceleration forces and vibrations during a flight into space.” As you can imagine, launching into space requires quite a bit of energy, and “‘during the launch phase, an astronaut has to endure a force of up to four times their own body weight. Ill-fitting dental fillings could become loose or fall out, and the atmospheric pressure change may be painful when cavities are present.’”

If you’ve ever gotten a toothache from flying on a plane with a cavity or tooth root infection, you might have experienced a minute fraction of what an astronaut with a cavity might feel during launch. Under this sort of immense pressure, any even tiny gaps, spaces, holes, erosions, or imperfections in your teeth could become immediately (and possibly painfully) apparent. Strong teeth and gums are essential to help the body more easily absorb potent shocks.

Furthermore, there isn’t typically a dentist aboard the ISS, so it would be much more difficult to treat any dental conditions that did arise. According to space magazine ROOM: “currently no procedure or technology is available to sustain and restore teeth during long-term missions, with the only planned and well-documented oral examination in space dating back to 1973.”

Astronauts must also keep their teeth in good shape for returning to Earth because “when space station residents are done with their time in orbit and return home, it’s also a violent trip.” The vehicle most ISS visitors take home “is still speeding at about 6.2 miles per hour…when it touches down.” This intense journey could also jostle and worsen any damage to your teeth.

Dental Health Can be a Serious Issue for Space Missions

In addition to enduring the tremendous physical pressure they experience, it’s important for astronauts to maintain their dental hygiene because (as we briefly discussed above) it’s more challenging to provide dental treatments and procedures in space.

Fortunately, according to ROOM, “the occurrence of dental injuries has been minimal…in the history of human spaceflight,” probably because “astronaut candidates are screened for dental issues [and]…expected to adhere to a meticulous oral hygiene routine and maintain good oral health.” This suggests that oral health in space is so important that a person who was otherwise qualified might not be able to become an astronaut if he or she didn’t have sufficiently healthy teeth.

Sadly, even with these parameters on astronaut oral hygiene in place, “a recent analysis of all medical conditions determined that the one condition most likely to result in a crew member’s departure from the International Space Station (ISS) is a dental abscess.” Mayo Clinic defines a tooth abscess as “a pocket of pus that’s caused by a bacterial infection.” This can be very uncomfortable, plus it can leave the rest of the mouth at risk if the infection spreads. Abscessed teeth may need root canal therapy and a dental crown or even extraction and a dental implant. The ISS probably has to send astronauts with abscesses back to Earth for treatment because this condition can be dangerous and cannot be easily treated on the space station.

The ISS is close enough to Earth to send astronauts with major dental problems back down for treatment, but for longer-term missions, like trips to Mars, oral health becomes an even bigger issue. According to a 2012 NASA Review of Spaceflight Dental Emergencies, “if an exploration mission [extending beyond Earth’s orbit] extends beyond a year, then there will be a greater lapse since the crew members’ last terrestrial dental exams…This increased time since professional dental care could increase the chance of a dental emergency….[which would] have to be treated in-flight with available resources and personnel who may not have extensive training in dental care. Thus, dental emergencies are an important risk to assess in preparation for exploration missions.”

Essentially, since dental care must be professionally evaluated and maintained at least annually (and we recommend every six months), NASA scientists must consider how longer missions would affect astronauts’ oral health. This means that the danger of cavities and infections could be a very real impediment to exploring the rest of our solar system and beyond. In this way, NASA is confirming what Dr. Flanagan and our Houston dental team already knew: preserving your oral health is critical!

The NASA report concluded that “long-duration missions raise the probability of a significant in-flight dental emergency” and, in reviewing past events, “preflight events requiring root canals had the potential for significant mission impact and occurred within close proximity to launch.” Issues involving the pulp, or inner blood, tissue, and nerves of the tooth, were of particular concern. Thus, the scientists concluded: “exploration missions will need to focus on preflight and in-flight prevention as well as preparing crew members by training them how to treat dental emergencies.” One of the most important “in-flight prevention” methods is, of course, regular tooth brushing.

How Astronauts Brush

We’ve learned that dental hygiene is extremely important for astronauts, but how do they actually brush their teeth? After all, there are no water faucets in space to rinse with, since, as Canadian astronaut Chris Hadfield puts it in his video about brushing his teeth in space, “you can’t have a tap, you can’t have a sink, ‘cause water would flow everywhere.” In Chris’s demonstration in zero gravity, he first squeezes a ball of water out of a water pack. Then, he puts that ball of water onto the toothbrush, making it thoroughly moist, and sips up any extra droplets that could hover around the cabin.

Next, Chris takes a regular toothbrush tube and squeezes out just a little bit. As he puts it, “not too much, because you’re gonna have to clean it up later.” As Chris puts away his toothpaste, his toothbrush simply floats in front of his face. Next, he brushes his teeth like we all do here on Earth. He scrubs his teeth with the brush. Ideally, we’ll remind you, you’ll want to clean your teeth for at least two minutes, being careful not to scrub too hard, and making sure to get all of your tooth surfaces. As Chris says, “get ‘em all, especially the ones in the back.” We agree!

When Chris is done, though, he doesn’t have anywhere to spit out his toothpaste, water, and spit, so he has to simply swallow it. As he notes, “it’s edible, won’t kill you.” He’s right, but we don’t recommend swallowing your toothpaste unless you’re in space. Then, to clean his toothbrush, Chris squeezes a bit more water into his mouth, sticks his toothbrush in to rinse it off, swallows the water, and voila! He’s done. The process is not terribly different from that on Earth. Some people worry that astronauts will end up with toothpaste up their noses, but “it doesn’t go up your nose, there’s nothing to push it up your nose, it just floats, so it works fine.”

Why Good Dental Hygiene is Astronomically Important for All

Even if you’re not an astronaut facing the monumental pressure of launch and spending months in space away from any sort of dental care, it’s still critical that you brush your teeth every day! The American Dental Association recommends that you “brush your teeth twice a day with a soft-bristled brush” with “your toothbrush at a 45-degree angle to the gums.” If you don’t, you could leave your mouth open to cavities and gum disease, as well as other uncomfortable and unsightly conditions. You should also floss at least once per day, as flossing is the only way to reach the areas between your teeth and under the gum line, where food particles and bacteria can easily become trapped.

Furthermore, we urge you to come in for a preventive care visit at least once every six months. This appointment gives Dr. Flanagan the opportunity to check your teeth and gums for any issues, which can be more easily remedied the earlier they are found. As we discussed above, even NASA has reported on the risks of going without regular professional dental care.

Learn More About Brushing at Our Houston Dental Practice

If you haven’t seen us for a professional dental cleaning and examination in at least six months then Houston, we’ve got a problem. Contact us today to schedule an appointment! When you come in, we’d be happy to share our dental hygiene tips and even discuss astronauts’ oral health further. We look forward to seeing you!